Member can join without ticking checkbox

Latest buddypress and wpmu and tos plugin.

A person can register without ticking the tos checkbox. Do I need to make the field mandatory somewhere? Its on the buddypress register (subscribe-now) page. If they don't enter their name, email address etc it prompts you and does not let you continue, however it doesn't matter if the tos checkbox is ticked or not. I've uninstalled the plugin and reinstalled and checked that there isn't an old version in the mu-plugins folder.

I've deactivated it for now until I understand what's going on.

Any ideas most appreciated. Thanks.